1. Field of the Invention
This invention pertains generally to the field of aircraft display units that provide information to the pilot or flight crew of an aircraft.
2. Description of the Related Art
Aeronautical Radio, Incorporated (“ARINC”) has published ARINC Specification 661 entitled “Cockpit Display System Interfaces to User Systems” (“ARINC 661”), an industry standard which defines an architecture to facilitate a creation of interactive displays. ARINC 661 standardizes the fundamental building blocks of cockpit avionics displays by providing specifications that separates graphics from logic, defines a runtime architecture, and defines a communication protocol. The contents of ARINC 661 are known to those skilled in the art.
The Cockpit Display System (“CDS”) may display widgets to the end user, where ARINC 661 specifies a standard set of widgets to develop a cockpit display; a widget may be considered as a displayable entity that is either interactive or non-interactive. At startup, the CDS loads and displays widgets listed in Definition Files (“DFs” or singularly, “DF”). Each DF is comprised of one or more layers, which are hierarchical listing of widgets that are loaded along with their initial properties such as, but not limited to, visibility and enablement. A DF may be associated with a User Application (“UA”).
ARINC 661 architecture separates graphics from logic. A UA may be connected to one or more layers and owned by an aircraft system and programmed with the logic for providing updated data via widget parameters to the CDS and reacting to user interactions with a display unit. Examples of aircraft systems that could own one or more UAs include, but are not limited to, air conditioning, auto flight, communications, electrical power, equipment and furnishings, fire protection, flight controls, fuel, hydraulic power, ice and rain protection, instruments, landing gear, lights, navigation, oxygen, pneumatic, vacuum, waste/water, central maintenance system, auxiliary power unit, propellers, main rotor, main rotor drive, tail rotor, tail rotor drive, rotors flight control, propeller/rotor systems, and powerplant systems.
In addition, ARINC 661 recommends a bi-directional runtime communication protocol for the exchange of data and events. In addition, ARINC 661 specifies how each widget interacts with end-users, the CDS, and the UAs.
Although ARINC 661 provides a standard for cockpit avionics displays, ARINC 661 does not provide for security rules that may be necessary for displaying multi-levels of classified information with unclassified information. Moreover, without the implementation of safeguards and additional precautions or rules for ensuring the security of classified information, the use of ARINC 661 may result with the unwanted and/or improper presentation of classified information to a person who has not been cleared to receive such classified information.